Race Shop: No Clutch Slippin’

Is your bike short on power? Does it seem to fall on its face faster than it did a week ago? Do you feel like you’re riding your little brother’s Big Wheel on a tile floor when you hop on your 250? If you answered yes to any of the above questions, there’s a good chance that you are facing a problem that is all too common in our sport: clutch slippage. If you think about it, the clutch on a motocross bike is one of the most abused parts there is, and unfortunately, even with constant transmission oil changes, clutch replacement is just a fact of life that we must accept when we throw a leg over the saddle. There is, however, some good news. With the proper technique it is possible even for fumbling magazine editors like ourselves to change a clutch in around ten minutes. Little tricks like not having to remove the rear brake pedal offer some solace and permit riders to swap clutch plates in between motos and in other high-stress moments with relative ease. We turned to TheEdgeSports.com factory mechanic Billy Felts for some advice on how he performs rapid clutch changes on Michael “The Burner” Byrnes’ KX250, and he jumped at the opportunity to help us out. The former Team Green rider and ex-mechanic for riders like Robbie Skaggs and Larry Ward knows a thing or two about clutches, especially considering the fact he changes them weekly for his rider. The first question we asked Felts was how he knows when a clutch is burnt, and what can be done to squeeze as much life as possible from it. “For the average rider, clutch plates generally need to be changed every five or six races, but if your bike feels down on power or like it’s climbing through the rpm range too quickly, then it’s probably time for replacement,” said Felts. “Keeping clean, fresh tranny oil in your bike and maintaining proper adjustment on the cable are important steps to getting maximum life from your clutch. Generally, I recommend between five and eight millimeters of cable play-it should be relaxed at all times. Remember, if your cable has any tension on it whatsoever, it’s making the clutch slip.”

Felts added that if you are experiencing slippage but still have plenty of adjustment at the cable, you can usually get at least a couple more weeks of use out of the clutch with some cable tweaking. Once you’ve determined that the plates finally are expired, though, it’s time to make the change to fresh ones before you start losing races due to burnt plates. Felts brought Burner’s KX down to our shop to guide us through the process, and here’s what we learned…